Non-linear analysis for a natural circulation boiling channel

The non-linear dynamics of a two-phase natural circulation boiling channel were investigated in this study, by employing the Galerkin nodal approximation method based on the homogeneous flow model. A stability map, which confirms the presence of an instability region under the condition of low exit quality, was obtained. Theoretical results indicate that the oscillation frequency in this low quality region is significantly smaller than that for the density wave oscillation. The model was also utilized to study the transient behavior of the channel following a step change of power. Theoretical results further revealed that an oscillating channel can be stabilized by a change of power from the unstable region to the stable region. ((orig.))